Volcanism, cyclones, earthquakes and forest fires are such natural phenomenons which cause destruction for mankind.
One of the first things to understand when working with natural disasters is the difference between natural phenomena, natural hazards, and natural disasters. Surprisingly, the definition of and distinction between these concepts is poorly documented. Here we’ll try to clear some things up, or at least give a sense of how muddy the water is.
Natural phenomena are physical events which are generally separated into categories such as atmospheric, geologic, and hydrologic phenomena, as well as other categories and sub-categories. Well-known examples of natural phenomena include hurricanes, earthquakes, floods. Less common examples include debris flows, waterspouts, and insect plagues. Natural phenomena are simply events; there is no implication about an event’s relation to humans. The concept includes events with potentially minimal immediate risk to humans such as fog or a solar eclipse. Defining individual phenomena can be tricky, because a single phenomena may trigger several different natural phenomena. For example, a storm may trigger flash flooding, strong winds, fires, hail, or other events.
Natural hazard is often treated as a synonym for natural phenomenon. However, the phrase “natural hazard” usually includes an implication that the natural phenomenon under discussion has the potential to cause damage to humans, human structures, or human activities. In this sense, one could view natural hazards as a poorly-defined subset of “potentially dangerous” natural phenomena. Some texts (ex. “Natural Disasters” by Patrick L. Abbott) refer to natural hazards as measuring the probability of the occurrence of a dangerous event, rather than referring to a subset of phenomena. This usage of the term is uncommon.
Natural disaster refers to an event which had a “major” impact on humans, and in that sense is a subset of natural hazards, and in turn a subset of natural phenomena. It is widely agreed that a natural hazard of a given magnitude is not necessarily a natural disaster. The line separating natural disasters from natural hazards is purely a function of damages to people or human infrastructure. However, there is no commonly agreed upon definition precisely separating natural hazards from natural disasters.